What can I do about ground hum?

Originally posted Nov-01-2012

Question: I keep noticing a ground hum, though my friends swear they can’t hear it. I’ve unplugged every other device in my listening room and still it won’t go away. What can I do?

Answer: Again, we refer to John Klintz’s expertise.
Have an electrician come out! With older homes, you can never be sure how the wiring was done. In one case, the listening room was on the top floor on the opposite side of the house from the basement washing room, but for some reason, the washer and dryer were on the same circuit. It wasn’t logical at all, but once the electrician pulled new wire to separate the listening room, all that buzzing disappeared. It might be a pricey investment, but better to protect your gear and sound for the future.
In a lot of cases a dedicated power line is the remedy for hum and other nasty side effects of a crowded AC line on your audio system(s). Whilst you're at it, replace the AC wall sockets with quality ones like PorterPort, Afterburner 8, Maestro or IME best the Furutech GTX-D (r).  I hear no hiss/hum in my all tube gear with my ear next to the tweeter when I hit the pause button with the volume playing around 92db. It was not possible before I got the dedicated lines (and good tubes).

On top of that I would add those cheap little ferrite cores on every device in-house that may inject "dirty" AC power back to the distribution panel like the fridge, washing machine (anything with an AC motor); fluorescent light is a main but unexpected source, replace them with eco-friendly LED lights if you can.

Every piece of equipment has at least two ground paths between them; the signal (RCA, XLR, not optical) cables and the power cords, often the speaker cables add another dimension. So star grounding is imperative. You can spend an huge amount on an ultra-high end box like the Troy Tripoint or try a DIY solution a la Audience adept Response or simply a brushed (yes it makes a difference) copper rod with 10ga copper wires to the units.

Ground lifting (with cheater plugs or AC power cord with just the L+N act like painkillers, yes you get instant gratification but the "ailment" needs to cured long term (unless you have vintage gear with no ground scheme).

I can not emphasize the importance of clean power, there is a reason that high end gear have besides excellent and often innovative designs a great deal of material cost and attention dedicated just for the power supply.
Many by now know that you can upgrade an entry level streamer device like the Logitech Touch or a very affordable DAC like the iFi iDAC / microDSD with an after market linear power supply to yield an organic and detailed sound similar to a device in the $2k range. Of course, this combo is less aesthetically pleasing than the mid to higher end one box with probably a brushed aluminium front plate. Whatever floats your boat.

BTW I have no affiliation to any of the above mentioned brands.

Just my 2 cents and as always, YMMV.  Keep on tweaking...